Tuesday, August 02, 2011

Reversals of consensus in medical science

My so-far fruitless quest continues for precedent to the denialist claim of incompetence and corruption in climate science. Some skeptics rely on the Galileo Fallacy - "people laughed at Galileo, people are laughing at me, therefore I am Galileo". Others try and find a more reasonable precedent in the last several centuries, and look to medical science as an example.

So there's an interesting blog post on a paper (the paper's behind a paywall, sadly) on medical retractions, claiming a 13% reversal rate on prior consensus for medical practices. To me, that's kind of high and uncomfortable in thinking about medicine, but its application as precedent doesn't quite work. First, these are claims of reversal, not a broad acceptance that the previous consensus was incorrect. And we're talking about consensus that e.g., a previous surgical practice was helpful when a new study contradicts it, a relatively technical level of detail in medical science. Claims that adding CO2 doesn't warm the planet is closer to contradicting germ theory in medical science, a fundamental consensus that hasn't been overturned.

The paper author also thinks the time interval for reversals to occur is about a decade. The modern consensus on climate goes back at least to the mid-1980s, or late-1800s if you consider the basic science. No precedent here. (UPDATE: per the comments, no consensus in the 1800s on the human effect, but there was a consensus about greenhouse gases and CO2. See the link for more info.)

Skeptics have used ulcers as one example of consensus reversal. It would be interesting to see whether the previous belief that stress caused ulcers was a best guess rather than a foundational theory in medicine. More to the point, though, what does a denialist with an ulcer do for treatment today? I suspect the smarter ones usually rely on consensus, rather than make "argument from authority" statements and attempt to rethink medical science for themselves. When you're looking to take action or make policy, trying to cast aside consensus and reinvent science on your own isn't likely to lead to a happy outcome.